Burger King's Halloween campaign this year revolves around a special green bun called the "Nightmare King" that the brand has proven--well, sort of--will give you nightmares.

The burger, as well as the green sesame seed bun, contain innocent-sounding ingredients such as savory flame-grilled beef, chicken fillet, melted American cheese, thick cut bacon, creamy mayonnaise, and onions, but a film by agency David Miami suggests they're anything but. 

It details how the brand carried out sleep studies on 100 participants at a sleep and neuro clinic in Florida, showing that the people were 3.5 times more likely to have nightmares after eating the burger. ("Someone in my dream turned into the burger," relates one woman-- somewhat chillingly.)

While we can't be certain that the bad dreams aren't simply the aftermath of eating something atypically green, having wires fixed to your scalp and sleeping in a hospital bed attached to machines, it's certainly an original Halloween idea. Plus, people can also order the burger to be delivered to their door via Postmates--making it an unusual Halloween gift.  It will be available for a limited time beginning October 22^, for $6.39.